On Sunday, after spotting what seemed to be a new kind of self-driving vehicle, we followed it. The customized Toyota Highlander (model year 2014 or later, according to resident car expert Bryan Logan) was brimming with sensors and other gear. And it sported a custom paint job that seemed designed to keep it under the radar (at least, as much as that's possible for an autonomous vehicle).

Check out the pictures below for a closer look at this mysterious vehicle:

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We spotted the vehicle on Sunday afternoon in the Bernal Heights neighborhood of San Francisco, which is near the Mission.

Luc Oreskovic

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We hit the gas and pulled up close behind so we could get a better look.

Luc Oreskovic

We noticed a few curious things right away. The vehicle appears to be a Toyota Highlander, yet the Toyota insignia has been removed from the oval-shaped space above the license plate. The entire body of the vehicle was painted a matte black that gave the vehicle an intriguing and stealthy profile.

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Notice the four, puck-like gizmos.

Luc Oreskovic

These appear to be LiDARs— the laser sensors used to create high-resolution maps and to let cars "see" and navigate their surroundings autonomously. There were four more of these LiDARs mounted on the front of the car, for a total of 8.

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The top of the car had some other interesting gear, including what appeared to be multiple video cameras and other strange-looking sensors.

Luc Oreskovic

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Here's another look at the vehicle's collection of roof-mounted hardware.

Luc Oreskovic

The black box-like items on the right and left each appeared to have a camera lens tucked inside.

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We got a better look at the vehicle as it turned left (perhaps to try to evade us).

Luc Oreskovic

This gives you a better look at the hardware in the front of the vehicle.

We pulled up alongside the SUV and confirmed there was a person in the passenger seat, but he ignored our requests to roll down his window and answer our questions.

Herger pointed us to this video from a conference in LA at the end of July, in which Zoox CEO Tim Kentley-Klay discusses his company's efforts and shows a video clip of a very similar vehicle. "Our ambition is not to create a so-called self driving car," Kentley-Klay says in the video. "Our ambition is to make the most advanced autonomous mobility experiences the world has ever seen."

Zoox certainly has the resources. The company recently poached a team of 17 auto engineers from Apple and hired a former NHTSA administrator, according to a Bloomberg report, which says Zoox has a private market valuation of $1 billion.